Emmalie Sanders, Dale G. Nimmo, James M. Turner, Skye Wassens, Damian R. Michael
{"title":"让拉卡利成为焦点：探测难以捉摸的半水栖哺乳动物的创新方法","authors":"Emmalie Sanders, Dale G. Nimmo, James M. Turner, Skye Wassens, Damian R. Michael","doi":"10.1071/wr24002","DOIUrl":null,"url":null,"abstract":"<strong> Context</strong><p>Freshwater ecosystems rank among the most threatened environments on Earth. Monitoring aquatic and semi-aquatic species is vital to informing conservation of freshwater ecosystems. However, many semi-aquatic mammals can be difficult to detect with conventional survey methods.</p><strong> Aims</strong><p>We aimed to identify the most effective survey method for detecting an Australian semi-aquatic mammal, the rakali (<i>Hydromys chrysogaster</i>).</p><strong> Methods</strong><p>We compared rakali detection rates among camera-trapping, live-trapping and visual surveys, and tested the influence of camera angle, trap proximity to water and time of survey, across the Yanco Creek system in southern New South Wales.</p><strong> Key results</strong><p>Nocturnal spotlight surveys were the most effective method for detecting rakali, with most observations occurring while individuals were foraging or swimming in the water. Camera traps facing a floating platform and cage traps mounted on floating platforms performed better than those deployed on land. Downward-facing camera traps detected rakali three times more often than did forward-facing cameras. Trapping rakali was unreliable, with the species detected at fewer than half of the sites where presence was confirmed via visual observation and camera traps. For species absence to be determined with 95% confidence, 2–4 weeks of nightly trapping is required, compared with six nights of visual surveys or 12 nights for a platform-facing camera. Morning visual surveys were largely ineffective because of predominantly nocturnal rakali activity and difficulty in detecting signs in creek environments.</p><strong> Conclusions</strong><p>The likelihood of detecting rakali can be maximised through the use of nightly spotlighting and deployment of baited camera traps focussed on platforms or natural resting areas within a water body.</p><strong> Implications</strong><p>Understanding the effectiveness of each method is essential for developing species-appropriate protocols for population monitoring. Our findings present suitable options to be further explored among the 100-plus small (<1 kg) semi-aquatic mammals worldwide that share similar behaviours and characteristics to the rakali, many of which are threatened or data deficient.</p>","PeriodicalId":23971,"journal":{"name":"Wildlife Research","volume":"34 1","pages":""},"PeriodicalIF":1.6000,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Putting rakali in the spotlight: innovative methods for detecting an elusive semi-aquatic mammal\",\"authors\":\"Emmalie Sanders, Dale G. Nimmo, James M. Turner, Skye Wassens, Damian R. Michael\",\"doi\":\"10.1071/wr24002\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<strong> Context</strong><p>Freshwater ecosystems rank among the most threatened environments on Earth. Monitoring aquatic and semi-aquatic species is vital to informing conservation of freshwater ecosystems. However, many semi-aquatic mammals can be difficult to detect with conventional survey methods.</p><strong> Aims</strong><p>We aimed to identify the most effective survey method for detecting an Australian semi-aquatic mammal, the rakali (<i>Hydromys chrysogaster</i>).</p><strong> Methods</strong><p>We compared rakali detection rates among camera-trapping, live-trapping and visual surveys, and tested the influence of camera angle, trap proximity to water and time of survey, across the Yanco Creek system in southern New South Wales.</p><strong> Key results</strong><p>Nocturnal spotlight surveys were the most effective method for detecting rakali, with most observations occurring while individuals were foraging or swimming in the water. Camera traps facing a floating platform and cage traps mounted on floating platforms performed better than those deployed on land. Downward-facing camera traps detected rakali three times more often than did forward-facing cameras. Trapping rakali was unreliable, with the species detected at fewer than half of the sites where presence was confirmed via visual observation and camera traps. For species absence to be determined with 95% confidence, 2–4 weeks of nightly trapping is required, compared with six nights of visual surveys or 12 nights for a platform-facing camera. Morning visual surveys were largely ineffective because of predominantly nocturnal rakali activity and difficulty in detecting signs in creek environments.</p><strong> Conclusions</strong><p>The likelihood of detecting rakali can be maximised through the use of nightly spotlighting and deployment of baited camera traps focussed on platforms or natural resting areas within a water body.</p><strong> Implications</strong><p>Understanding the effectiveness of each method is essential for developing species-appropriate protocols for population monitoring. Our findings present suitable options to be further explored among the 100-plus small (<1 kg) semi-aquatic mammals worldwide that share similar behaviours and characteristics to the rakali, many of which are threatened or data deficient.</p>\",\"PeriodicalId\":23971,\"journal\":{\"name\":\"Wildlife Research\",\"volume\":\"34 1\",\"pages\":\"\"},\"PeriodicalIF\":1.6000,\"publicationDate\":\"2024-05-31\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Wildlife Research\",\"FirstCategoryId\":\"99\",\"ListUrlMain\":\"https://doi.org/10.1071/wr24002\",\"RegionNum\":3,\"RegionCategory\":\"生物学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"ECOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Wildlife Research","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1071/wr24002","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ECOLOGY","Score":null,"Total":0}
Putting rakali in the spotlight: innovative methods for detecting an elusive semi-aquatic mammal
Context
Freshwater ecosystems rank among the most threatened environments on Earth. Monitoring aquatic and semi-aquatic species is vital to informing conservation of freshwater ecosystems. However, many semi-aquatic mammals can be difficult to detect with conventional survey methods.
Aims
We aimed to identify the most effective survey method for detecting an Australian semi-aquatic mammal, the rakali (Hydromys chrysogaster).
Methods
We compared rakali detection rates among camera-trapping, live-trapping and visual surveys, and tested the influence of camera angle, trap proximity to water and time of survey, across the Yanco Creek system in southern New South Wales.
Key results
Nocturnal spotlight surveys were the most effective method for detecting rakali, with most observations occurring while individuals were foraging or swimming in the water. Camera traps facing a floating platform and cage traps mounted on floating platforms performed better than those deployed on land. Downward-facing camera traps detected rakali three times more often than did forward-facing cameras. Trapping rakali was unreliable, with the species detected at fewer than half of the sites where presence was confirmed via visual observation and camera traps. For species absence to be determined with 95% confidence, 2–4 weeks of nightly trapping is required, compared with six nights of visual surveys or 12 nights for a platform-facing camera. Morning visual surveys were largely ineffective because of predominantly nocturnal rakali activity and difficulty in detecting signs in creek environments.
Conclusions
The likelihood of detecting rakali can be maximised through the use of nightly spotlighting and deployment of baited camera traps focussed on platforms or natural resting areas within a water body.
Implications
Understanding the effectiveness of each method is essential for developing species-appropriate protocols for population monitoring. Our findings present suitable options to be further explored among the 100-plus small (<1 kg) semi-aquatic mammals worldwide that share similar behaviours and characteristics to the rakali, many of which are threatened or data deficient.
期刊介绍：
Wildlife Research represents an international forum for the publication of research and debate on the ecology, management and conservation of wild animals in natural and modified habitats. The journal combines basic research in wildlife ecology with advances in science-based management practice. Subject areas include: applied ecology; conservation biology; ecosystem management; management of over-abundant, pest and invasive species; global change and wildlife management; diseases and their impacts on wildlife populations; human dimensions of management and conservation; assessing management outcomes; and the implications of wildlife research for policy development. Readers can expect a range of papers covering well-structured field studies, manipulative experiments, and analytical and modelling studies. All articles aim to improve the practice of wildlife management and contribute conceptual advances to our knowledge and understanding of wildlife ecology.
Wildlife Research is a vital resource for wildlife scientists, students and managers, applied ecologists, conservation biologists, environmental consultants and NGOs and government policy advisors.
Wildlife Research is published with the endorsement of the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the Australian Academy of Science.
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